Feeding of humpback whales in low latitudes of the Southeast Pacific Ocean

Abstract

Humpback whales perform long migrations from their breeding and nursing areas at low latitudes to feeding grounds at high latitudes. Nonetheless, this strictly dichotomous paradigm of migration is challenged by accumulating examples of occasional or regular feeding at low latitudes for several stocks worldwide. Here, we report multiple evidences of “Stock G” humpback whales feeding in coastal waters, at low latitudes of the Southeast Pacific Ocean. Lunge feeding behavior and defecation were observed in Ecuador, while both lunge- and trap feeding in pursuit of Peruvian anchovy was documented in northern Chile. A photographically re-sighted individual feeding at different latitudes of Chile suggested potential site fidelity to two foraging areas. Whether these feeding behaviours are novel due to changes in prey distribution, intensifying competition from a growing humpback whale population, or simply reflect vastly increased research effort remains unknown. Further research into the feeding ecology of Stock G should help reveal historic and potentially new feeding grounds, prey composition and precise migration paths. Competition from anchovy fisheries, vessel collision and net entanglement are suspected threats.

Keywords

• megaptera novaeangliae
• feeding grounds
• trap feeding
• lunge feeding
• humboldt current
• peruvian anchovy
• phylopatry